As shown in FIGS. 1 to 3, a conventional linear guide includes a guide rail 81, a slider 82 slidably striding the guide rail 81, a plurality of rollers 83 disposed between the guide rail 81 and the slider 82, two end caps 84 mounted on two sides of the slider 82, two end seals 9 respectively secured on the end caps 84, a plurality of screws 85 (only one is shown in FIG. 1) disposed to fasten the end caps 84 and the end seals 9 to the slider 82, and a grease nipple 86 for introducing lubricant grease. The guide rail 81 has two raceway grooves 811 at left and right sides. Each end seal 9 has two contact portions 90 extending in the raceway grooves 811 for removing grease, dust and foreign objects in the grooves 811. The rollers 83 are ball bearings for facilitating smooth movement of the slider 82 on the guide rail 81. The end seals 9 are disposed to seal lubricant grease stored inside the slider 82, and scrape dust and foreign objects on the guide rail 81 to prevent the dust and foreign objects from entering the slider 82 and further adversely affecting rolling of the rollers 83.
Referring to FIGS. 1, 2 and 4, each end seal 9 includes a metal-made main plate 91 and a plastic-made cladding member 92 attached to the main plate 91. The main plate 91 includes an upper portion 911, two lower contact portions 912 disposed below the upper portion 911 and spaced apart from each other, and a deflecting portion 913 extending from the upper portion 911 to engage the contact portions 912. The main plate 91 has opposite first and second major surfaces 914, 915 defined by the upper portion 911, the lower contact portions 912 and the deflecting portion 913. The upper portion 911 has two fastened holes 916 for passage of screws 85, and a through hole 917 for receiving the grease nipple 86. With the deflecting portion 913 that interconnects the upper portion 911 and the lower contact portions 912, the lower contact portions 912 are disposed remote from the respective end cap 84 relative to the upper portion 911.
Referring to FIGS. 2, 4 and 5, the cladding member 92 includes a first cladding portion 921 attached to the first major surface 914 at the lower contact portions 912 so as to be coplanar to the upper portion 911, and a second cladding portion 922 attached to the second major surface 915.
In making of the end seal 9, the main plate 91 is placed in a mold (not shown) where the fastened holes 916 and the through hole 917 are blocked. A molten plastic material is introduced into the mold to surround the main plate 91 and to cure so as to form the cladding member 92. To reinforce the connection between the cladding member 92 and the main plate 91, an adhesive is needed, and is disposed on the main plate 91 to adhere thereto through a coating process (e.g. spreading, dip coating, etc.). Subsequently, drying and plastic coating processes must be performed, which renders the fabrication of the end seal 9 troublesome and inconvenient.
Moreover, as shown in FIGS. 1, 4 and 5, since the first major surface 914 of the main plate 91 at the upper portion 911 that abuts against and is fastened to the end cap 84 is relatively rigid and is hence designed not to be surrounded by the softer cladding member 92, formation of the deflecting portion 913 is required such that the first cladding portion 921 of the cladding member 92 is attached only to the lower contact portions 912. However, under the circumstance that no cladding is applied to the upper portion 911 of the main plate 91 which is a thin metal plate, the mere structural strength of the end seal 9 is not sufficient enough, i.e. the end seal 9 is still liable to breakage at the upper portion 911 and detachment and split of the cladding member 92 below the through hole 917.